7 glioblastoma myths

BY
Shiao-Pei Weathers, M.D.

Glioblastoma is the most common and aggressive primary brain tumor in adults. Although it’s considered a rare cancer, with about 12,000 new diagnoses each year, it’s gained increased visibility recently with the diagnoses of a few high-profile people.

As a neuro-oncologist and the clinical medical director of MD Anderson’sBrain and Spine Center, part of my job is to make sure glioblastoma patients and their families understand this disease and how it will affect them. Unfortunately, as I’ve learned, there are many myths and misconceptions about glioblastoma.

Here’s the truth about seven glioblastoma myths I commonly hear.

1. Myth: Cell phones cause glioblastoma.

Fact: Cell phones don’t cause brain cancer. Several different studies have failed to find clear evidence of a link between cell phone use and brain cancer. The number of people diagnosed with glioblastoma has remained largely stable over the past decade, while cell phone use has continued to increase.

2. Myth: There’s nothing you can do for an “inoperable” glioblastoma.

Fact: A tumor that’s considered “inoperable” at a hospital without specialized brain tumor programs may actually be operable if you seek treatment at a cancer center with the right expertise. Here at MD Anderson, our neurosurgeons successfully operate on many patients who thought their tumors were inoperable. We treat glioblastoma patients every day and have a great deal of experience and expertise in safely removing tumors. This includes glioblastomas involving brain regions responsible for important functions, such as language or movement.

Fact: Even a successful gross total resection for glioblastoma always leaves behind microscopic disease. Glioblastoma has “tentacles” that reach out from the main tumor mass. These tentacles are invisible to the naked eye and even to many of our most advanced imaging technologies. A gross total resection of a brain tumor is defined as removing at least 98% or more of the contrast-enhancing tumor, which is the part of the tumor that we can see on the MRI scan when the patient is given contrast dye through an IV. An MD Anderson analysis showed that glioblastoma patients who have a gross total resection tend to live longer. However, invisible cells of cancer are always left behind in the brain after surgery. That’s why the standard-of-care treatment for glioblastoma includes chemotherapy and radiation, even after an excellent surgical resection.

4. Myth: Radiation therapy is the same for any brain tumor.

Fact: Most patients undergoing radiation therapy for glioblastoma receive photon-based radiation therapy, such as intensity-modulated radiotherapy (IMRT). IMRT uses multiple X-ray beams made of photons at different angles to treat the area where the tumor was removed and any tumor left behind, even if it’s just microscopic disease. Radiation is carefully planned and targeted to protect the healthy, normal brain.

Patients with other types of brain tumors or who require radiation to both their brain and spine may receive a different type of radiation therapy, including proton therapy. To date, proton therapy has not been shown to be more effective than the standard photon-based radiation for glioblastoma. Multiple ongoing clinical trials are investigating and further defining the role of proton radiation in brain tumors.

5. Myth: The ketogenic diet can cure glioblastoma.

Fact: No diet can cure glioblastoma. A handful of case studies and internet bloggers have claimed the keto diet may have benefits for brain cancer patients, but the idea that you can “starve” glioblastoma through diet is a myth. While the role of diet in cancer is an area of active research, we know that glioblastoma patients need nutrients – including carbohydrates – to keep their bodies strong through treatment. We recommend a balanced diet based on the New American Plate guidelines developed by the American Institute for Cancer Research.

6. Myth: Having glioblastoma means your family is at increased risk for developing a brain tumor.

Fact: Glioblastoma is a brain tumor that almost always develops sporadically. Being diagnosed with glioblastoma does not mean your children or siblings are more likely to develop glioblastoma or another brain tumor. Some very rare cancer syndromes, such as Li-Fraumeni Syndrome, are associated with an increased risk for developing brain tumors and other cancers, but these patients usually are diagnosed with multiple types of cancer at a very young age.

BRCA mutations are associated with an increased risk for developing breast and ovarian cancer, but there is no known association between BRCA mutations and glioblastoma development. A few ongoing genetic studies are looking at families that have multiple relatives with brain tumors to better understand if certain inherited genes contribute to brain tumor development.

7. Myth: Chemotherapy always makes your hair fall out.

Fact: The most commonly used chemotherapy for glioblastoma is called temozolomide (TMZ), and hair loss isn’t typically one of the side effects of this chemotherapy. However, treating glioblastoma with radiation therapy to the brain can cause hair loss around the part of the head where the radiation beam enters. After radiation is complete, the hair almost always grows back.